[Greenbuilding] looking for best 4' and 8' fluorescent shop light

[Reuben Deumling]

Thanks for your detailed response, David. I've interspersed my answers and
further questions below.

On Tue, Oct 4, 2011 at 1:28 PM, David Bergman <bergman at cyberg.com> wrote:

>
> 1. Are you talking about bare-bulb down lights? Surface-mounted? Suspended?
>
surface mounted - if by bare-bulb down you mean just the tube with nothing
in front of it, yes.

> 2. How high is the ceiling?
>
6' now; 8' after I raise the house :-)

> 3. How dark are the surfaces in the space?
>
lots of variation. Ultimately the white/reflective surfaces will be
few/mostly covered up by darker objects.

> 4. How much brightness do you need/want?
>
I have a 9W and a 25W CFL in the 11x24 space now. That is o.k. but I'd like
a bit more light.

> 5. How even do you want/need the lighting to be?
>
Ideally with tubes the light could be distributed a bit more evenly/widely.
This is my basement shop. I can and probably will have a few
machine-specific task lights as well so I figured two 4' or even two 8'
lights would do it--ideally single tube fixtures if those exist (fewer
watts, and I'd hope/assume that 2x32W would be more than enough given all of
the above. I certainly don't want 2x64W!)

> 6. How often will the lights will be on? (If infrequently, perhaps you
> needn't agonize so much over getting the highest efficacy.)
>
As someone whose electrical demand used to be 9watts, I strive for the
best/lowest, but I am also a cheapskate so hope to find some happy medium.
Hours/day: sometimes none; other times 6 -8 hours or more.

>
> And probably some other variables as well.
>
> If you're talking about direct downlight, the efficacy will just be a
> matter of the lumen output divided by the watts. There's no significant
> efficiency loss due to the fixture (i.e. no shade/diffuser) assuming a
> decent reflector above the bulbs. There is some variation in ballast
> efficacy, but I suspect that so long as you select an Energy Star labelled
> electronic ballast, the difference isn't that great.
>

Is it still the case (as I surmise from your last paragraph) that I have to
mix and match these components? I can't just order up a handful of XYZ
lights that already combine the a sensible/high efficiency
ballast+lamp+fixture package?

>
> Another minor variable: colder color/higher temperature fluorescents will
> usually have a higher efficacy.
>
> You can also dig a bit into http://www.nema.org/lampballastmatrix/
>
> This database,
> http://www.energystar.gov/index.cfm?c=lighting.pr_lighting_subcomponents ,
> is still under development.
>
>
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